Testing to determine capability in a particular field has long been of interest. Testing is used in virtually all areas of academics, enterprise and government to evaluate candidates seeking certification in certain professional capacities, including real estate, law, medicine, etc. As in any testing environment, attempts to achieve an unfair advantage, or to profit from capturing information about such a test, are a reality.
Examples of attempts to achieve an unfair advantage include pre-knowledge, that is, gaining access to test items (e.g., questions) before the beginning of a test, proxy testing, a situation where a person represents himself or herself as being another person during the test, and item harvesting, the intent to capture test content for the purpose of distribution to later test takers.
Test developers or psychometricians routinely analyze both operational items (questions that contribute towards a candidate's score) and pretest items (field questions that do not contribute towards a candidate's score). A primary purpose of analyzing operational items is to verify the key, or correct answer, to questions prior to computing and reporting scores. Pretest items are similarly analyzed in order to assess item quality for possible inclusion on future exams. In addition to these routine analyses, operational and pretest response data can also be analyzed to assess possible threats to the security and therefore, integrity, of the exam. This line of analysis is commonly referred to as “outlier detection,” and is a subarea of a larger topic, “data forensics.”